Melanoma is a type of skin cancer that occurs in melanocytes, the cells that produce pigment in the skin. It is one of the deadliest forms of skin cancer, with a high risk of metastasis and a poor prognosis in advanced stages.
While traditional cancer treatments such as chemotherapy and radiation therapy have shown limited success in treating melanoma, targeted drug therapy has emerged as a promising new approach. This blog explores the latest advances in targeted therapy for melanoma, including its use for different types of melanoma skin cancer and its potential to supplement other treatments.
Understanding Targeted Therapy
Targeted therapy is a type of cancer treatment that aims to target specific molecules or pathways that are involved in the growth and spread of cancer cells. The key difference between targeted therapy and traditional chemotherapy is the specificity with which these treatments target cancer cells. While chemotherapy medications have an impact on any cells that grow quickly - both healthy and cancerous - targeted therapy is more specific and is focused exclusively on cancer cells.
Targeted drug therapy works by targeting particular elements of the cancer cells and preventing them from dividing, ultimately stopping the growth and spread of cancer. On the other hand, chemotherapy is only designed to destroy existing cancer cells, meaning that the threat of relapse may still be present.
Targeted therapies can be delivered in a variety of ways, including oral medications, intravenous infusions, or injections.
Targeted Therapy for Treating Melanoma Skin Cancer
Targeted therapy for cancer has revolutionised the treatment of melanoma, offering improved outcomes for patients with this deadly form of skin cancer. Some of the key targeted therapies for melanoma skin cancer include:
BRAF is a gene that is mutated in approximately 50% of melanomas. BRAF inhibitors such as vemurafenib and dabrafenib work by blocking the activity of the mutated BRAF protein, which leads to the death of cancer cells. BRAF inhibitors have been shown to improve response rates and prolong survival in patients with advanced melanoma.
MEK is a downstream effector of the BRAF pathway, and MEK inhibitors such as trametinib and cobimetinib work by blocking the activity of MEK, which leads to the death of cancer cells. MEK inhibitors are often used in combination with BRAF inhibitors to improve outcomes for patients with advanced melanoma.
KIT is a receptor tyrosine kinase that is mutated in a small percentage of melanomas. KIT inhibitors such as imatinib and dasatinib work by blocking the activity of the mutated KIT protein, which leads to the death of cancer cells.
Checkpoint inhibitors such as ipilimumab and nivolumab work by stimulating the immune system to recognize and attack cancer cells. Checkpoint inhibitors have been shown to improve response rates and prolong survival in patients with advanced melanoma.
Targeted Therapy Approach for Mucosal Melanoma
Mucosal melanoma is a rare form of melanoma that occurs in the mucous membranes of the body, such as the nasal passages, mouth, and genital tract. It is a highly aggressive form of melanoma skin cancer with a poor prognosis and limited treatment options.
Recent studies have shown that mucosal melanomas have a lower frequency of BRAF mutations compared to cutaneous melanomas, making BRAF inhibitors less effective in this population. However, other molecular targets have been identified, including c-KIT, a protein involved in cell growth and survival. Imatinib, a drug that targets c-KIT, has shown promising results in early studies, with response rates of up to 50%.
Targeted Therapy Approach for Ocular Melanoma
Ocular melanoma is a rare and aggressive cancer which develops in the uveal tract of the eye. Different from cutaneous melanoma, ocular melanoma is characterised by mutations in GNAQ or GNA11. As a result of these mutations, a signalling pathway known as the MAP kinase pathway is activated, encouraging the growth and survival of cells.
In recent years, scientists have developed drugs such as selumetinib and binimetinib that target this specific pathway. Early studies indicate these drugs have had successful response rates of between 40% and 50%. Thus, providing new hope for treating this rare cancer.
Enhancing Melanoma Treatment: Combining Targeted Therapy With Additional Treatments
While targeted therapy has shown great promise in the treatment of melanoma, it is unlikely to be a stand-alone treatment. Combining targeted drug therapy with other treatments, such as immunotherapy or radiation therapy, may offer improved outcomes for patients with melanoma.
Immunotherapy is a type of cancer treatment that works by stimulating the immune system to recognize and attack cancer cells. Several immunotherapy drugs have been approved for the treatment of melanoma, including checkpoint inhibitors such as ipilimumab and nivolumab. Combining targeted therapy with checkpoint inhibitors has been shown to improve response rates and prolong survival in patients with advanced melanoma.
Radiation therapy, which uses high-energy radiation to kill cancer cells, has traditionally been used to treat localised melanoma. However, recent studies have shown that radiation therapy may also have a role in the treatment of metastatic melanoma. Combining radiation therapy with targeted therapy has been shown to improve response rates and delay the development of drug resistance.
Frequently Asked Questions
How Long Does Targeted Melanoma Therapy Take?
The duration of targeted therapy for melanoma skin cancer can vary depending on the specific treatment, the stage of cancer, and how the patient responds to the treatment. In some cases, targeted therapy can be given as a short-term treatment course lasting a few months. In other cases, targeted therapy may be given as a long-term maintenance treatment to keep cancer under control.
What Are the Side Effects of Targeted Therapy for Melanoma?
Like any cancer treatment, targeted therapy for melanoma can have side effects. The specific side effects will depend on the type of targeted therapy used, as well as the individual patient's health status and medical history. Common side effects of targeted therapy for melanoma may include:
It is important to discuss any side effects with the oncologist, as they may be able to recommend strategies to manage or alleviate them.
How Much Does Targeted Therapy Cost?
The cost of targeted therapy for cancer can vary widely depending on the specific treatment, the length of treatment, and other factors such as the patient's insurance coverage. In general, targeted therapy tends to be more expensive than traditional chemotherapy. However, many patients can access targeted therapy through their insurance coverage, and some pharmaceutical companies offer financial assistance programs to help patients afford the cost of treatment.
Who is a Candidate for Targeted Therapy?
Patients with melanoma who have specific genetic mutations, such as mutations in the BRAF or NRAS genes, may be candidates for targeted therapy. In addition, targeted therapy for cancer may be an option for patients with advanced or metastatic melanoma who have not responded well to other treatments. The decision to use targeted therapy will depend on many factors, including the patient's overall health, the stage of cancer, and the specific genetic mutations present in the cancer cells.